This is the "Light Context" template. It should be called in the following format:

{{Light Context
|Supercontext=
|Topcontext=
|Toppage=
|Sequence number=
|Context type=
|Heading=
|ImageMap template=
|Start date=
|End date=
|Summary=
|Show referred by=
|Referred by text=
|EMM access control=
}}

Edit the page to see the template text.